Piano action



March 7, 1933. c; H, DASENBROK 1,900.488

PIANO ACTION Filed Oct. 26, 1951 Z SheetS-Sheet 1 Inverna/ $7 WWW+ W.

March 1933- c. H. DASENBROOK ,900,488

PIANO ACTION.

Filed 001;. 2a 1931- ZShets-Sheet 2 Patented Mar. 7, 1933 UNITED STATESCHARLES H. DASENBROOK, F ROCKFORD,

ILLINOIS, ASSIGNOR TO THAYER ACTION COMPANY, OF ROCKFORD, ILLINOIS, ACORPORATION OF ILLINOIS PIANO ACTION Application filed October 26, 1931.Serial 110,570,995.

This invention relates in general to the improvements in grand pianoactions and more particularly to a so called simplified action in whichthe functions of the conventional repetition lever and associated partsare performed by a metallic spring.

The general object of the invention is to provide a novel repetitionspring in a piano action of the above character whereby to duplicate thekey touch, the rugged construction and the reliability of operation ofrepetition mechanisms heretofore employed while at the same time greatlysimplifying the construction of the action and reducing the cost ofmanufacture accordingly.

More particularly, the invention resides in the novel construction ofthe repetition spring, in the new and improved manner of mounting thesame, and in the novel construction of the different spring stops.

Other objects and advantages of the invention will become apparent fromthe following detailed description taken in conjunction with theaccompanying drawings, in which Figure 1 is a fragmentary sideelevational view of a grand piano action embodying the features of thepresent invention, the parts being in the positions which they assumejust prior to withdrawal of the jack while the 39 key is beingdepressed.

Fig. 2 is a perspective View of a portion of the mechanism shown inFig. 1. p

Fig. 3 is a view similar to Fig. 1 showing a modified form of theinvention with the parts in normal position of rest.

Fig. 4 is a view similar to Fig. 3 showing different positions of theparts.

F ig. 5 is a perspective view of the modified form of repetition spring.G In the exemplary form shown in the drawings, the numeral 6 indicatesthe conventional form of key lever carrying the backcheck 7 and thecapstan screw 8 which latter enga es the whip 9 and throws the same up-:5 ward y upon depression of the key. Herein the whip is pivoted at 10upon an arm 11 depending from a rail 12 which carries the reboundcushion. The butt 14 of the hammer is pivoted at15 on the forwardly pro-0 jecting flange 16 of a rail 17 and carries a limited by engagement ofan adjustable and forwardly projecting button 24 on the jack with avertical post 25.

The present invention contemplates a novel repetition spring indicatedgenerally by the numeral 26 which is simple and inexpensive to constructand assemble in the action, which requires no mechanical adjustingmeans, which is suited for use with several differently Weightedhammers, which operates at maximum mechanical advantage in sustainingthe weight of the hammer during recovery of the jack, which utilizes toadvantage the upward movement of the whip in increasing the springeffect thereby permitting the use of a relatively light springconstruction. To this end a spring is employed which has an elongatedsubstantially straight portion 27 extending in a direction generallyparallel to a line betweenthe axes 10 and 15 and a reversely bentportion 28 which enables the spring to be anchored near the end of thewhip remote from the pivot there- Preferably, the spring is of thehair-pin type being composed of a single length of resilient wire bentat its center so that the portions 27 and 28 are each composed of twoparallel parts spaced apart to receive the upper ends of the jack 19 andthe post 25 between them. The upper or closed end portion 27 is bentdownward slightly at its free end and adapted to engage-a cushionedbutton 29 the stem of which is threaded into the butt flange 16 beyondthe axis 15. In this way the button 29 acts as a stop for limiting thebackward movement of the jack 19 and the button is located close to theknuckle 18 v a made woodwi-th a heavy base 3l' (Fig. 1)

having parallel sides. In this preferred form of spring, the lengths ofwire forming the open "end portion 28,,aresubstant1ally straight. anddisposed in" horizontal grooves 32 formed in the opposite sides of thepost. The ends of the Wire are bent toward each other and project intothe post at one end ofthc groove thereby effectually anchoring such endsthe opposite ends of the groove, the wires are'firmly anchored by tacks33 driven into the post with'their heads overlying the wires. 1 In thisway the unsupported portions of the wires are firmly heldagainstilateral as well as vertlcal' movement and this combined with thedoublerwire construction gives a substantial degree of lateral rigidityto the spring as a whole enabling e the parts of the closed end portion27 to be spaced relatively close to the p0st'25 and the jack 19and yetmaintained at all times out of rubbing contact'therewith.

It will be apparent that the entire length of spring between the pointof contact with the knuckle l8 and the point of anchorage in the post 25is rendered effective with the mounting above described. Thus, thespring possesses ahighdegree of fleXibility and is of substantiallyuniform strength regardless of ordinary variations in construction andmounting during manufacture. For this reason, no provision foradjustment is required and springs of the same size wire may be usedforseiteral differently weighted hammers'and'only a few different s zesof Wire are required for all of the hammers 1n the 1 action. anchoringthe spring at a'point remote from the whip pivot'lO, that is, adja centthe jack 19,-it-will be observed that full advantageis taken of theupward movement of the whip inbending the springdownwardly and therebyincreasing the spring effect the time when the spring comes into play insustaining the weight of'the hammer during recovery o f the jack. Thespring may therefore be made of; minimum weight and high flexibilitytherebymaking for greater uniformity in the construction of the springs.

Another way of anchoring the spring in the base of the post 25isillustratecl in Figs. 3 and 4 In this instance the ends 34k of thewire forming-the. spring are bent downwardly into substantially rightangular relation with respect to the portions 28 and secured to thepostin the samemanner as in the, formfirst described which latter, ispreferred because of the greater lateral rigidity obtained. f v The rest5. s lseu ili e .1 me s for preventing application of the spring effectshoulder 35 which is padded with a piece of a felt 36 and isi ofsufiicientleng'th of (iverlie the legs 27 of the spring and engage thesame J as shownin Fig. 2. Application of spring pressure to the hammerwhen the parts are in idle position is thereby prevented. With theshoulder thus located, the costof attaching the pad 36 is reduced to aminimum inasmuch as it may be applied in strlp form to a plurality ofpostsrlisposed side by side.

Preferably the shoulder 35 is formed on the post directly oppositefromthe jack in order to form an obtuse anglewiththe side of the I postwithwh ich it intersects thereby further facilitating attachment of thepad 36 Assumingthe parts to be in idle position (Fig. 3), the actionoperates as follows.

When the key is depressed, the whip is thrown upwardly and its motiontransmitted I to the hammer through the jack. The latter is withdrawnfrom beneath the butt knuckle 18 as the arm 2Q engages the stop 21 andthe I momentum of the hammer carries the latter upwardly against thestring If the blow is a sharp one andthe-key is held depressedthereafter, the back-check 7 comes into play as shown in full lines inFig. 4 and the spring 26 is movedaway from the shoulder 36 and the stop29 thereby exerting its force on the Ina similar way as shown in vhammer. v dotted outl ne in 4, the spring 26is out of contact with theshoulder 36 and engaging the butt knuckle following a-light 'blow'.

the stop 29 is positioned to limit t-he nove" ment of hammer by thespring to a point where the jack just engagesthe knuckle in recoveringthe operator senses the reco very of the jack-the. same asinconventional piano actionsusing repetition levers. In this way the keytouch of present day actions is closely simulated and all of thefunctions of the conventional repetition lever and associated parts areperformed by the spring 26 which can be'manufactured and assembled" thect o a ewb n a y du ed o ti- I claim. as, myinvention: i

1. In a piano action, the combination of v a pivot ally mounted hammerhaving a butt Now as the key is released under either of I knuckle, apivotally mounted whip adapted to be actuated by depression of a. key, ajack pivoted on the free end of said whip and adapted toengage at itsfree end with said knuckle, a post rigid with and upstanding from saidwhip adjacent the jack pivot, and an elongated repetition spring bentintermediate its ends to form an acute angle between its end portions,one of said portions extending in a'direction generally parallel to saidwhip and anchored in said post,

the other end portion of said" spring extending substantially parallelto a: line through the axes of said whip and hammer with its free endadapted-to-engage said knuckle whereby to sustain the weight of thelatter during recovery of said jack.

2.In a piano action, the combination of a pivotally mounted hammerhaving a butt knuckle, a pivotally mounted whip adapted to be actuatedby depression of a key, a jack pivoted on the free end of said whip andadapted to engage at its free end with said knuckle, a post rigid withand upstanding from said whip adjacent the jack pivot, an elongatedspring of the hair-pin type bent intermediateits ends to form an acuteangle between its open and closed end portions, the ends of said openportion lying on opposite sides of said post and rigidly anchoredtherein, the wires forming said closed end por tion being disposed onopposite sides of said post and said jack and adapted to engage saidknuckle adjacent the closed end of the spring.

3. In a piano action, the combination of a pivotally mounted hammerhaving a butt knuckle, a pivotally mounted whip adapted to be actuatedby depression of a key, a jack pivoted on the free end of said whip andadapted to engage at its free end with said knuckle, a post ri id withand upstanding from said whip a jacent the jack pivot, an elongatedpiece of resilient wire bent at its center to form a spring of thehair-pin type bent intermediate its ends to formopen and closed endportions extending at an acute angle to each other, substantial lengthsof the wires forming said open portion being disposed in grooves onopposite sides of said post with the ends of the wire bent toward eachother and projecting into the post near one end of said grooves andtacks driven into the post adjacent the opposite end of the grooves withtheir heads overlying the wire, the closed end portion of said springbeing arranged for engagement with the under side of said knuckle.

4. In a piano action, the combination of a pivotally mounted hammerhaving a butt knuckle, a pivotally mounted whip adapted to be actuatedby depression of a key, a jack pivoted on the free end of said whip andadapted to engage at its free end with said knuckle, a post rigid withand upstanding from said whip adjacent the jack pivot, an elongatedpiece of wire bent at its center to form a spring of the hair-pin typehaving open and closed end portions with the former anchored in saidpost, said closed end porpivoted on the free end of said whip and Fadapted to engage at its free end withsaid knuckle, a post rigid withand upstanding from said whip adjacent the jack pivot, an elongatedpiece of wire bent at its center to form a spring of the hair-pin typehaving open and closed end portions with the ends of the wire disposedon opposite sides of said post and anchored therein to support vsaidclosed end portion, the lengths of wire forming the latter beingdisposed on opposite sides of said post and jack and spaced so as to beout of rubbing contact therewith but'engageable with said knuckle, andcushionedshoulders formed on said post at the upper end thereof to limitupward flexing of said sprin 6. n a piano action, the combination of apivotally mounted hammer having a butt knuckle, a pivotally mounted whipadapted to be actuated by depression of a key, a jack pivoted on thefree end of said whip and adapted to engage at its free end with saidknuckle, a repetition spring of thelhair-pin type having an elongatedsubstantially straight closed end portion extending in a Y directiongenerally parallel to a line through the axes of said hammer and whipand adapted to engage the under side of said knuckle, and a single postrigid with and upstanding from said whip providing an anchor for theopen end portion of said spring and a stop for limiting the upwardmovement of saidclosed end portion. A

7. In a piano action, the combination of a pivotally mounted hammerhaving a butt knuckle, a pivotally mounted whip adapted to be actuatedby depression of a key, a jack pivoted on the free end of said whip andadapted to engage at its free end with said knuckle, an elongatedrepetition spring supported by said whip and having a vertically movablesubstantially straight portion adapted to engage said knuckle, a postrigid with and upstanding from said whip and having a shoulderconstituting a stop for limiting the upward movement ofsaidportion andformed on the'side of said post adjacent said jack, said shoulderextending across the entire width of the post and pro- I jecting beyondthe opposite sides thereof,

and a strip of cushioning material on the surface of'said shoulder. 1

' 8. In a piano action, thecombination of a pivotal'ly mounted hammerhaving a butt knuckle, a pivotally mounted whip adapted to be actuatedby depression of a key, a jack pivoted on the free end of'said Whip andadapted to'enga ge at its free end with said kniiclilie',an elongatedrepetition spring supported by said whip and having a verticallymovable" substantially straight portion adapted to el-igagesaidknuckle,and a post i. no

rigid with and upstanding from said whip and having an elongatedshoulder extending transversely of said post with its ends projectingbeyond opposite sidesthereof and providing stops for engaging"saidportion and thereby limiting upward "movement thereof, the plane ofthe shoulder. surface forming an obtuse angle with the side of the postfrom which the shoulder is out. w

9. In a piano action, the combination of a pivotally mounted hammerhaving a butt knuckle, a pivotally mounted whip adapted to 'be'actuatedby depression of a key, a jack pivoted on the free end of said whip andadapted to engage at its free end with said knuckle, an'elongatedrepetition spring supported by said whip and having a vertically movablesubstantially straight portionadapted to engage said knuckle, and a postrigid with and upstanding from said whip and having a downwardly facing,shoulder formed by :l-rollowing out said post on the side alongwhichsaid spring portion extends, asecond shoulder intersecting saidfirstmentioned' shoulder and formed by hollowing out key, ajackpivo-tedon the free-end-ofsaid whip and adapted to engage atitsfreeend with saidknuckle, a post rigid with and'upstanding from said, whipadjacent the jack pivot, an elongated wire member bent intermediate itsendstoformtwo substantially straight legs projecting toward said 7 jackat an acute angle relative to each other, one extending in agenerally'horizontal direction and having its free end anchored in saidpost at a point spacedabove'said jack, the other of said legs extendingupwardly toward said jack and engageable, adjacent its free s end withsaid, knuckle, and a cushioned shoulder on said post actingv on saidlast mentioned leg intermediate the ends thereof to limit upward flexingthereof; t Y

. In testimony whereohl'have hereunto affixed my signature; g CHARLESDASENBROOIQ;

a side of said post disposed transversely of said springportion, andcushioning means secured to and extending along said'second shoulder andoverlapping a portion of'said first mentioned shoulder. V v V 10. Ina'piano action, the combination of a 3 rail with a flange projectingtherefrom, a hammer having itsbutt end pivoted on said flange, akey-actuated whip, a Jack pivoted onsaid whip and adapted to engage abutt vknuckle on said butt end, an elongated repetition spring supportedfrom one of its ends 7 i by said whip and having the other end'extendingin a direction substantially parsaid flange between theedge thereof andthe axis of; said'h ammer soas to be disposed close to said knuckle, anda button on the end of said screw providing a cushioned stop for thefreeend of said spring and for limiting the withdrawing movement of saidjack.

11. In a piano action, the combination of a pivotally mounted hammerhaving a buttyknuckle, a pivotally mounted whip adapted to be actuatedby depression of a

